FTTH CPE landscape
nathan at atlasnetworks.us
Thu Aug 4 20:54:23 UTC 2011
> Why? As long as it can be a transparent router, why would it need to be
> a bridge?
Layer 2 CPE capability is a big deal, especially if you're doing unrouted multicast (see many TV/VoD over ethernet platforms for details). But it's also nice for handing the customer a layer-2 service port like they're used to getting, if they want it that way. The routing engine in CPE's is often simply not as capable as the bridging mechanism, so there's an end-user experience to consider.
It's also worth noting that this feature will probably become less important as IPv6 and DHCP6-PD becomes more widely deployed. Until then, the extra routing in IPv4 starts to chew up some serious address space if you're rolling out thousands or more of the CPEs. See most national ISP's CPE configuration if you think it's unusual to want to hand off services on a bridged interface- it's not, at all.
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